PR Checklist

Please check if your PR fulfills the following requirements:

• The commit message follows our guidelines: https://github.com/angular/angular/blob/main/contributing-docs/commit-message-guidelines.md
• Tests for the changes have been added (for bug fixes / features)
• Docs have been added / updated (for bug fixes / features)

PR Type

What kind of change does this PR introduce?

• Bugfix
• Feature
• Code style update (formatting, local variables)
• Refactoring (no functional changes, no api changes)
• Build related changes
• CI related changes
• Documentation content changes
• angular.dev application / infrastructure changes
• Other... Please describe:

What is the current behavior?

• On mobile and desktop, the version picker dropdown can't scroll to the last version, the bottom items sit below the visible viewport.
• On the tablet horizontal navbar, the dropdown opens off to the right of the trigger and overlaps the neighbouring nav items.

What is the new behavior?

• Dropdown scrolls to the last version on all viewports.
• On tablet, the dropdown opens directly below the version button, horizontally centered on it.

Does this PR introduce a breaking change?

• Yes
• No